The present invention relates to a method for characterizing an optical source. It also relates to a device for characterizing an optical source, and a system comprising such a device.
Such a device allows a user to characterize an optical source, for example a wavelength of a radiation emitted by this optical source.
Different devices are known in the state of the art for measuring a wavelength of a radiation emitted by an optical source.
These devices need to explore a range of possible wavelengths in order to determine which is the wavelength, from among those in the range, that is emitted by the source. This exploration can typically be carried out:                with a costly solution, and exploration by a photodiode array. Existing solutions propose Fabry-Perot configurations without moving mechanical parts, but with arrays as detector. The aspect without moving parts is a definite advantage for robustness and reliability. On the other hand, using detection arrays is a drawback with respect to the cost, in particular when it is a question of measuring wavelengths beyond 1100 nm and silicon can no longer be used. It is then necessary to turn to more expensive materials such as InGaAs for telecom wavelengths, or even PbSe or MCT for the mid-infrared. The arrays typically cost several thousand euros.        with a slow solution, and exploration by tunable Fabry-Perot. Tunable Fabry-Perot solutions do not use arrays, but only one or several photodiodes. However, in order to carry out the desired exploration and to obtain the desired information (position of the Fabry-Perot transmission peak), it is necessary to move one of the mirrors of the Fabry-Perot. This scanning significantly slows down the measurement. Indeed, an acquisition is necessary for each position of the mirror, instead of acquiring the entire interferogram simultaneously when using array detectors. For a typical response time of 0.1 ms and a measurement of 100 mirror positions the minimum time for one measurement is thus 10 ms, limiting the refresh rate to 100 Hz (without taking account of the processing time).        
The aim of the present invention is to propose a method and/or a device for characterizing an optical source, which allows characterization that is more economical and/or quicker than the state of the art.